Sunday, March 28, 2010

Dichroic glass pendants

Debbie's Pendant

Kate's Pendant

Phil's pendant, fresh out of the kiln

This past weekend, I added a class on dichroic glass pendants to my class schedule. The dichroic glass pieces I've done previously went through the firing with no problems. That wasn't the case this weekend.

The glass fuses to the metal clay at 1470 degrees for 45 minutes. But, that doesn't mean that the glass can just be laid on top of the clay. It needs to be contained by wrapping metal clay around it. Now, I'm not a physicist (I never even took chemistry or physics in high school. Little did I know how much art involves those two sciences.) I'm not exactly sure what the glass does during the firing process, but I imagine that it becomes sort of gelatinous.

When the firing is complete, the door of the kiln must be opened and left open until the internal temperature of the kiln reaches 1,000 degrees. Then the door is closed and left closed until the kiln is back to room temperature. This keeps the glass from turning cloudy which is known as devitrification and also keeps the glass from cooling too quickly and cracking.

Well, let me tell you that I followed the process to the T and still had problems. (Murphy's Law!!) My one piece turned cloudy and my other piece cracked. In fact the glass cab just cracked right off. (Thank goodness for E6000 glue.) Our pieces also looked like the glass was just getting ready to melt. The shape of the glass shifted just a little. Guess it's time to check the temperature of my kiln. (Once I figure out the directions on the set I bought to do just that.)

The good news is that none of my student's pieces turned cloudy or cracked. So, these are the pieces I'm showcasing on this post. I'll show you mine later.

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